This invention relates to the field of unloading devices for removing catalyst and beads from within the tubes of a multi-tube reactor. More particularly, this invention relates to improved nozzles for use in such devices.
In unloading flowable granular or particle catalyst from the tubes of a multi-tube reactor, difficulties have been encountered in removing catalyst that has become lodged within the tubes during reactor operation. In some previous instances, the particle catalyst completely blocked or bridged some or all of the tubes of the reactor due to the size and configuration of the catalyst or the support and inert beads used to hold the catalyst in place. This type of bridging or blocking impedes movement or flow of the catalyst and beads from the tubes of the reactor.
U.S. Pat. No. 3,916,960 has addressed the problem of removing the catalyst from such reactor tubes utilizing an apparatus comprising a head positionable adjacent open ends of a plurality of reactor tubes for creating a pressure differential in the reactor tubes for flowing the catalyst from the reactor tubes into a chamber formed by the head. However, because of the configuration of this apparatus, before it can be used, the reactor head must be removed so that adequate head space is available. Secondly, this apparatus has the disadvantage of not being able to remove either the larger size support beads used to hold the catalyst support material, nor the inert beads which are immediately adjacent to the catalyst. Both of these must be removed manually before the apparatus of U.S. Pat. No. 3,916,960 may be used to remove the catalyst.
Therefore, a means for removing catalyst from within the tubes of a multi-tube reactor whereby the top head of the reactor would not need to be removed, and whereby all of the material contained in the reactor tube including catalyst, inert and support beads could be removed in a one-step process would constitute a significant improvement over the prior art.